After he told you his origin story, he thought you would reject him. Just like his sworn brother did several years ago... He thought you would hit him or kick him out... But you just hugged him, held him close and said that everything would be fine...

And now, the guy had another nightmare about the fact that everyone found out who he is, that he is the heir of Kaenri'arch, everyone turned away from him and even you... Now he was snuggling like a little child to his mother.